The long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA) was evaluated in 124 patients who underwent PTCA between October 1982 and June 1985. Seventy-six patients had their proximal coronary arteries completely revascularized by PTCA (including repeat PTCA) and follow-up angiography showed the vessels were patent 3 to 6 months after the last intervention (group A). The other 48 patients showed incomplete revascularization (group B). The 10-year event-free survival rates from cardiac death and non-fatal myocardial infarction were 89.7% in group A and 93.5% in group B, respectively. Survival rates free from cardiac death, myocardial infarction, coronary bypass surgery, and repeat angioplasty for new lesions were 82.5% and 62.7%, respectively (p < 0.001). Ninety-nine percent of patients in group A and 79.5% of patients in group B were asymptomatic at the follow-up. Coronary angiography was performed in a total of 22 patients (19 patients in group A, 3 in group B). In group A, myocardial infarction occurred in one patient 8 years after PTCA. The infarct-related lesion seemed to be the same as the previous PTCA lesion. Although the other 20 PTCA lesions were all patent without progression, nine significant and new lesions were found on the coronary angiograms. Successfully revascularized vessels remained patent for over 10 years, but new lesions sometimes occur in segments other than the previously treated segment.